Apparatus and method for applying ciphering in a universal mobile telecommunications system

Abstract

Apparatus and a method for ciphering messages in mobile telecommunications system user equipment and network are disclosed. The apparatus is arranged to store a plurality of current ciphering configurations and/or a plurality of old (previously applied) ciphering configurations and/or a plurality of new (future) ciphering configurations. Thus different ciphering configuration may be applied at different times and for different radio bearers.

1 . A method for applying ciphering in a user equipment device (UE) for use in a mobile telecommunications system, the method comprising:
 selecting from a plurality of ciphering configurations stored in the UE, a subset of a plurality of ciphering configurations that may be used on a wireless communication;   determining which type of ciphering configuration to use on the wireless communication;   using one ciphering configuration from the selected subset on the wireless communication to generate a ciphered wireless communication; and   transmitting the ciphered wireless communication.   
     
     
         2 . The method according to  claim 1 , further comprising:
 receiving the wireless communication over a radio bearer (RB); and   in which selecting from the plurality of ciphering configuration comprises:
 selecting, from the plurality of ciphering configurations stored in the UE and based on the RB, the subset of the plurality of ciphering configurations; 
   and in which determining which type of ciphering configuration to use is based on the RB and the wireless communication.   
     
     
         3 . The method according to  claim 1 , wherein the types of ciphering configuration comprise at least one of the group comprising: new ciphering configuration, old ciphering configuration and ciphering configuration. 
     
     
         4 . The method according to  claim 1 , wherein a maximum limit is applied to the number of ciphering configuration of a given type that are stored. 
     
     
         5 . The method according to  claim 1 , further comprising determining whether parameters of a ciphering configuration are required, and removing parameters that are determined to be no longer required. 
     
     
         6 . The method according to  claim 1 , wherein the UE is capable of communicating via a plurality of radio bearers, the method further comprising storing parameters relating to a plurality of ciphering configurations for a given type of ciphering configuration for each RB. 
     
     
         7 . The method according to  claim 1 , further comprising storing parameters in a layer of a protocol stack which layer applies the ciphering. 
     
     
         8 . A mobile telecommunications device configured for use in a mobile telecommunications system, the device comprising:
 a receiver enabled to receive wireless communications; and   a microprocessor, memory, and software operable
 to select from a plurality of stored ciphering configurations; a subset of a plurality of ciphering configurations that may be used on a wireless communication; 
 to determine which type of ciphering configuration to use on the wireless communication; 
 to use one ciphering configuration from the selected subset on the wireless communication to generate a ciphered wireless communication; and 
 to transmit the ciphered wireless communication. 
   
     
     
         9 . The device according to  claim 8 , in which:
 the wireless communication is received over a radio bearer (RB);   the subset is selected based on the RB, and in which   the software is operable to determine which type of ciphering configuration to use based on the RB and the wireless communication.   
     
     
         10 . The device according to  claim 8 , stored ciphering configurations including at least one of the group comprising: new ciphering configuration, old ciphering configuration and ciphering configuration. 
     
     
         11 . The device according to  claim 8 , wherein a maximum limit is applied to the number configurations of a given type that are stored. 
     
     
         12 . The device according to  claim 8 , further arranged to determine whether parameters of a ciphering configuration are required, and to delete parameters that are determined to be no longer required. 
     
     
         13 . The device according to  claim 8 , further arranged to apply the appropriate ciphering configuration according to parameters stored with each ciphering configuration. 
     
     
         14 . The device according to  claim 8 , wherein the device is further arranged to store parameters associated with the ciphering configurations in a layer of a protocol stack which applies ciphering. 
     
     
         15 . The device according to  claim 13  wherein the device is operable in a Universal Mobile Telecommunications System and the parameters are stored in at least one of the Radio Link Control Layer and the Medium Access Control (MAC) layer of the protocol stack of the device. 
     
     
         16 . A mobile communications network comprising a network of a plurality of cells from a plurality of Node B transceivers and at least one radio network controller (RNC), comprising:
 a microprocessor, memory, and software operable
 to select, from a plurality of stored ciphering configurations, a subset of a plurality of ciphering configurations that may be used on a wireless communication; 
 to determine which type of ciphering configuration to use on the wireless communication; 
 to use one ciphering configuration from the selected subset on the wireless communication to generate a ciphered wireless communication; and 
 to transmit the ciphered wireless communication. 
   
     
     
         17 . The device according to  claim 16 , in which:
 the wireless communication is received over a radio bearer (RB);   the subset is selected based on the RB, and in which   the software is operable to determine which type of ciphering configuration to use based on the RB and the wireless communication.   
     
     
         18 . The network according to  claim 16 , the types of ciphering configuration being at least one of the group comprising: new ciphering configuration, old ciphering configuration and ciphering configuration. 
     
     
         19 . The network according to  claim 16 , wherein a maximum limit is applied to the number of ciphering configurations of a given type that are stored. 
     
     
         20 . The network according to  claim 16 , further arranged to determine whether parameters of a ciphering configuration are required, and to delete parameters that are determined to be no longer required. 
     
     
         21 . The network according to  claim 16 , further arranged to apply the appropriate ciphering configuration according to parameters stored with each ciphering configuration. 
     
     
         22 . The network according to  claim 16 , wherein the device is further arranged to store parameters associated with the ciphering configurations in a layer of a protocol stack which applies ciphering. 
     
     
         23 . The network according to  claim 16 , wherein the network is operable in a Universal Mobile Telecommunications System and the parameters are stored in at-least one of the Radio Link Control Layer and the Medium Access Control (MAC) layer of the protocol stack. 
     
     
         24 . The network according to  claim 16 , wherein the microprocessor, memory, and software reside on the NRC.